Read EDID for the 1st display for startup

ui/ozone/platform/dri/native_display_delegate_proxy.cc

Index: ui/ozone/platform/dri/native_display_delegate_proxy.cc
diff --git a/ui/ozone/platform/dri/native_display_delegate_proxy.cc b/ui/ozone/platform/dri/native_display_delegate_proxy.cc
index 29dc53805c62c6218fc9bb638bcf6360b65f6080..8ad2c40a46aa54222e93193ae09460c9290a125d 100644
--- a/ui/ozone/platform/dri/native_display_delegate_proxy.cc
+++ b/ui/ozone/platform/dri/native_display_delegate_proxy.cc
@@ -7,6 +7,7 @@
 #include <stdio.h>
 
 #include "base/logging.h"
+#include "base/threading/thread_restrictions.h"
 #include "ui/display/types/display_snapshot.h"
 #include "ui/display/types/native_display_observer.h"
 #include "ui/events/ozone/device/device_event.h"
@@ -63,9 +64,22 @@ void NativeDisplayDelegateProxy::Initialize() {
 
   if (!displays_.empty())
     return;
+  DisplaySnapshot_Params params;
+  bool success = false;
+  {
+    // The file generated by frecon that contains EDID for the 1st display.
+    const base::FilePath kEDIDFile("/tmp/display_info.bin");
+
+    // Just read it on current thread as this is necessary information
+    // to start. This access only tmpfs, which is fast.
+    // TODO(dnicoara|oshima): crbug.com/450886.
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    success = CreateSnapshotFromEDIDFile(kEDIDFile, &params);
+  }
 
-  DisplaySnapshot_Params params = CreateSnapshotFromCommandLine();
-  if (params.type != DISPLAY_CONNECTION_TYPE_NONE) {
+  // Fallback to command line if the file doesn't exit or failed to read.
+  if (success || CreateSnapshotFromCommandLine(&params)) {
+    DCHECK_NE(DISPLAY_CONNECTION_TYPE_NONE, params.type);
     displays_.push_back(new DriDisplaySnapshotProxy(params, display_manager_));
     has_dummy_display_ = true;
   }